Transcript Edward L. Thorndike
Edward L. Thorndike
• Animals placed in puzzle boxes • • String pulled, latch released, animal jumps out and receives food • Learning by random trial and error
Law of Effect
– Thorndike’s principle that responses are “stamped in” by rewards and “stamped out” by punishments.
B.F. Skinner
• • “Project Pigeon” –WWII Skinner suggested that pigeons be used to guide missiles to their targets
Operant
– voluntary responses that are reinforced –
Pecking at targets projected onto a screen
•
Reinforce
– To follow a response with a stimulus that increases the frequency of the response –
Food pellets
• Defense Department concluded that Project Pigeon was “for the birds”
Skinner Box
•
CC vs. OC
Operant conditioning investigates the influence of consequences on subsequent behavior.
• • •
Classical conditioning involuntary responses looks at conditioned such as eyeblinks or salivation, whereas Operant conditioning investigates the learning of voluntary responses such as pecking at a target or pressing a lever.
Where learning, operant conditioning R-->S classical conditioning learning.
illustrates S-->R is often viewed as It is the consequence that follows the response that influences whether the response is likely or unlikely to occur again.
B.F. Skinner
• Skinner Box – experimental conditions carefully introduced and removed and results on laboratory animals carefully observed.
• Rat deprived of food and placed in Skinner box with lever at one end • Rat accidentally presses lever and food pellet is released.
• After trial and error the rat begins pressing the lever to receive food.
• What is the operant?
–
Pressing the lever
• What reinforces the behavior?
–
Food pellet
Types of Reinforcers
• •
Positive Reinforcers
– A reinforcer that when
presented
increases the frequency of an operant.
Ex
. A hungry rat presses a bar in its cage and receives food. The food is a positive condition for the hungry rat. The rat presses the bar again, and again receives food. The rat's behavior of pressing the bar is strengthened by the consequence of receiving food.
Types of Reinforcement
• •
Negative Reinforcers
– A reinforcer that when
removed
increases the frequency of an operant.
Ex.
A rat is placed in a cage and immediately receives a mild electrical shock on its feet. The shock is a negative condition for the rat. The rat presses a bar and the shock stops. The rat receives another shock, presses the bar again, and again the shock stops
.
The rat's behavior of pressing the bar is strengthened by the consequence of stopping the shock.
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Positive or Negative Reinforcement?
Police pulling drivers over and giving prizes for buckling up.
A child snaps her fingers until her teacher calls on her.
A hospital patient is allowed extra visiting time after eating a complete meal.
Receiving a city utility discount for participating in a recycling program.
Grounding a teenager until his/her homework is finished.
A parent nagging a child to clean up her room.
A rat presses a lever to terminate a shock or a loud tone.
A professor gives extra credit to students with perfect attendance.
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PR 2.
NR 3.
PR 4.
PR 5.
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NR NR NR 8.
PR
Types of Reinforcers
• •
Primary Reinforcers
– An unlearned reinforcer.
Ex.
Food, water, adequate warmth (positive reinforcers) and pain (negative reinforcer) • •
Secondary Reinforcers
– A stimulus that gains reinforcement value through association with established reinforcers.
Ex.
Money, attention, social approval
POSITIVE REINFORCERS NEGATIVE REINFORCERS PRIMARY
Food
SECONDARY
Money
PRIMARY
Electric shock
SECONDARY
Rejection Water Sex Warmth Grades Status Praise Intense heat Pain of any sort Suffocation Failure Criticism Avoidance
Rewards and Punishments
•
Reward
– A pleasant stimulus that increases the frequency of the behavior it follows.
• Considered to synonymous with positive reinforcement.
•
Punishment
– An unpleasant stimulus that suppresses the behavior it follows.
• Usually better to reward children for desirable behavior.
• Pg. 160
Potential Negative Effects of Punishment
Antecedent Undesirable employee behavior Punishment by manager Short-term decrease in frequency of undesirable employee behavior
But leads to long-term Which tends to reinforce
Recurrence of undesirable employee behavior Undesirable emotional reaction Aggressive, disruptive behavior Apathetic, noncreative performance Fear of manager High turnover and absenteeism
Schedules of Reinforcement
• •
Continuous Reinforcement
– A schedule of reinforcement in which every correct response is reinforced.
Partial Reinforcement
of several reinforcement – One schedules in which not every correct response is reinforced.
• Which method do you think is used more in real life?
An Example of Continuous Reinforcement
• Each instance of a smile is reinforced
Schedules of Reinforcement
• Continuous reinforcement refers to reinforcement being administered to each instance of a response • Partial reinforcement lies between continuous reinforcement and extinction
Schedules of Reinforcement
• •
Ratio Version
– having to do with instances of the behavior.
Ex. –
Reinforce or reward the behavior after a set number or
x
many times that an action or behavior is demonstrated.
• •
Interval Version
– having to do with the passage of time.
Ex.
– Reinforce the student after a set number or
x
period of time that the behavior is displayed.
4 Basic Schedules of Reinforcement
• Fixed-interval schedule • Variable-interval schedule • Fixed-ratio schedule • Variable-ratio schedule
Fixed-Interval Schedule
• •
Fixed-interval schedule
– A schedule in which a fixed amount of time must elapse between the previous and subsequent times that reinforcement will occur.
• No response during the interval is reinforced.
• The first response following the interval is reinforced.
• Produces an overall low rate of responding
Ex.
I get one pellet of food every 5 minutes when I press the lever
Fixed Interval Reinforcement
Variable-Interval Schedule
•
Variable-interval Schedule
– A schedule in which a variable amount of time must elapse between the previous and subsequent times that reinforcement is available.
• • Produces an overall low consistent rate of responding.
Ex.
– I get a pellet of food on average every 5 minutes when I press the bar.
Variable Interval Reinforcement
Fixed-Ratio Schedule
•
Fixed-ratio Schedule
– A schedule in which reinforcement is provided after a fixed number of correct responses.
• These schedules usually produce rapid rates of responding with short post-reinforcement pauses • • The length of the pause is directly proportional to the number of responses required
Ex.
food – For every 5 bar presses, I get one pellet of
An Example of Fixed Ratio Reinforcement
• Every fourth instance of a smile is reinforced
Fixed Ratio Reinforcement
Variable-Ratio Schedule
•
Variable-ratio Schedule
– A schedule in which reinforcement is provided after a variable number of correct responses.
• • Produce an overall high consistent rate of responding.
Ex.
– On average, I press the bar 5 times for one pellet of food.
An Example of Variable Ratio Reinforcement
• Random instances of the behavior are reinforced
Variable Ratio Reinforcement
TYPE
Fixed Ratio
MEANING OUTCOME
Reinforcement depends on a definite number of responses Activity slows after reinforcement and then picks up
Variable Ratio
Number of responses needed for reinforcement varies
Fixed Interval
Greatest activity of all schedules Reinforcement depends on a fixed time Activity increases as deadline nears
Variable Interval
Time between reinforcement varies Steady activity results
Comparisons of Schedules of Reinforcement SCHEDULE Fixed interval Fixed ratio Variable interval Variable ratio FORM OF REWARD INFLUENCE ON PERFORMANCE EFFECTS ON BEHAVIOR Reward on fixed time basis Leads to average and irregular performance Reward tied to specific number of responses Leads quickly to very high and stable performance Fast extinction of behavior Moderately fast extinction of behavior Reward given after varying periods of time Leads to moderately high and stable performance Reward given for some behaviors Slow extinction of behavior Leads to very high performance Very slow extinction of behavior
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FI, VI, FR, or VR?
When I bake cookies, I can only put one set in at a time, so after 10 minutes my first set of cookies is done. After another ten minutes, my second set of cookies is done. I get to eat a cookie after each set is done baking.
After every 10 math problems that I complete, I allow myself a 5 minute break.
I look over my notes every night because I never know how much time will go by before my next pop quiz.
When hunting season comes around, sometimes I’ll spend all day sitting in the woods waiting to get a shot at a big buck. It’s worth it though when I get a nice 10 point.
Today in Psychology class we were talking about Schedules of Reinforcement and everyone was eagerly raising their hands and participating. Miranda raised her hand a couple of times and was eventually called on.
1. FI 2. FR 3. VI 4. VI 5. VR
FI, VI, FR, or VR?
6. Madison spanks her son if she has to ask him three times to clean up his room.
7. Emily has a spelling test every Friday. She usually does well and gets a star sticker.
8. Steve’s a big gambling man. He plays the slot machines all day hoping for a big win.
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Snakes get hungry at certain times of the day. They might watch any number of prey go by before they decide to strike.
10. Mr. Vora receives a salary paycheck every 2 weeks. t 11. Christina works at a tanning salon. For every 2 bottles of lotion she sells, she gets 1 dollar in commission. 6. FR 7. FI 8. VR 9. VI 10. FI 11. FR 12. Mike is trying to study for his upcoming Psychology quiz. He reads five pages, then takes a break. He resumes reading and takes another break after he has completed 5 more pages.
12. FR
FI, VI, FR, or VR?
13. Megan is fundraising to try to raise money so she can go on the annual band trip. She goes door to door in her neighborhood trying to sell popcorn tins. She eventually sells some.
14. Kylie is a business girl who works in the big city. Her boss is busy, so he only checks her work periodically.
15. Mark is a lawyer who owns his own practice. His customers makes payments at irregular times.
16. Jessica is a dental assistant and gets a raise every year at the same time and never in between.
17. Andrew works at a GM factory and is in charge of attaching 3 parts. After he gets his parts attached, he gets some free time before the next car moves down the line.
18. Brittany is a telemarketer trying to sell life insurance. After so many calls, someone will eventually buy.
13. VR 14. VI 15. VI 16. FI 17. FR 18. VR
Applications of Operant Conditioning
• •
Programmed Learning
– A method of learning in which complex tasks are broken down into simple steps, each of which is reinforced. Errors are not reinforced.
Ex
. – Hooked on Phonics
Applications of Operant Conditioning
• •
Socialization
– Guidance of people into socially desirable behavior by means of verbal messages, the systematic use of rewards and punishments, and other methods of teaching.
Ex.
– Children play with other children who are generous and non-aggressive and avoid those who are not.
Applications of Operant Conditioning • Behavior Modification
Praise this Ignore this
Applications of Operant Conditioning
• •
Token Economy
– An environmental setting that fosters desired behavior by reinforcing it with tokens (secondary reinforcers) that can be exchanged for other reinforcers.
Ex
. – Book It!
Other Types of Learning
• • •
Insight Learning
– In Gestalt psychology, a sudden perception of relationships among elements of the “perceptual field”, permitting the solution of a problem.
Latent Learning
or concealed.
– Learning that is hidden
Observational Learning
– Acquiring operants by observing other engage in them.
Insight Learning
• Wolfgang Kohler – German Gestalt psychologist • Experiments with Chimpanzees • Sultan learned to use a stick to rake in bananas placed outside his cage.
• When the bananas were placed outside of Sultan’s reach, he fitted two poles together to make a single pole long enough to reach the food
Insight Learning
• • “Aha” Learning
Cognitive Map
representation or “picture” of the elements in a learning situation, such as a maze.
– – A mental
Ex.
– if someone pukes in the hall that you usually take to your next class you will still be able to find your way because of your mental representation of this school.
Insight Learning
Latent Learning
• E.C. Tolman – experiment with rats.
• Rats learn about their environments in the absence of reinforcement.
• Some rats went through maze for food goals, while others were given no reinforcement for several days.
• After 10 days, rewards were put in with the rats that had previously been given no rewards for 2 or 3 trials. • Those rats reached the food box as quickly as the rats that had been getting reinforcement for over a week.
• Rats learn about mazes in which they roam even if they are unrewarded for doing so.
Observational Learning
• Albert Bandura • Bobo doll experiment • Assistant placed in room with doll • Beat doll with hammer and hit doll • Kindergarten children watched this display of aggression in a separate room.
• When placed in the room, they too were extremely aggressive with the doll • Happened without ever being rewarded for the behavior.
• http://www.npr.org/templa tes/story/story.php?storyI
d=1187559
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Modeling
Monkey see, monkey do!
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Disinhibition
Get away with or are rewarded for violence They always “get the girl/guy/money/car - etc.
•
Increased arousal
Works the audience up Watch the fans at a sporting event Watch your friends watch the WWF •
Habituation
We become used to - desensitization
1. Violent behavior is not representative of most people 2. Violent behaviors are not real - special effects and technology 3. Most people use other than non-violent means to resolve conflict Mediation Arbitration Negotiation
Other
•Positive modeling •Encourage other activities •Monitor - watch first, watch with, explain •Limit time •Abiding by rating system •Act - call legislators •Watch educational programs